Anotace:
In order to solve the problem of poor bonding and easy peeling of reinforced concrete structure strengthened by steel wire mesh and polymer mortar (SWM-PM). In this paper, a steel wire mesh and polyurethane cement (SWM-PUC) composite strengthening technique is presented. The flexural properties of one unreinforced beam, two SWM-PM strengthened beams and four SWM-PUC composite strengthened beams were studied experimentally. The experimental results show that the SWM-PUC composite reinforcement layer can improve the load carrying capacity and rigidity of reinforced concrete beams and limit the unfolding cracks significantly. The SWM-PUC composite strengthened beams have pure bending damage and peeling damage between the strengthening layer and the concrete has not occurred. However, SWM-PM strengthened beams with the same SWM reinforcement ratio occurred with peeling damage between the reinforcement and the concrete. On basis of an experimental study, the theoretical formulas for cracking load, ultimate load, deflection and width of crack of SWM-PUC composite strengthened beams are proposed by the simplified stress-strain constitutive relation of the material and the theoretical formulas are deduced with the code. By contrasting the test results with the theoretical computation results, the accuracy of the experiment results and the reliability of the theoretical formulas were verified.